This invention generally relates to surgical devices, systems, and methods, and more particularly provides structures and techniques for manually aligning a robotic surgery system with a desired surgical site.
In robotically assisted or telerobotic surgery, a surgeon typically operates a master controller to control the motion of surgical instruments at the surgical site. The controller may be separated from the patient by a significant distance (e.g., across the operating room, in a different room, or in a completely different building than the patient). Alternatively, a controller may be positioned quite near the patient in the operating room. Regardless, the controller will typically include one or more hand input devices (such as joysticks, exoskeletal gloves, or the like) which are coupled by a servomechanism to a surgical instrument. More specifically, servo motors articulate the surgical instrument based on the surgeon""s manipulation of the hand input devices. During an operation, the surgeon may employ, via the robotic surgery system, a variety of surgical instruments, such as tissue graspers, needle drivers, electrosurgical cautery probes, etc. Each of these structures perform functions for the surgeon, for example, holding or driving a needle, grasping a blood vessel, or dissecting, cauterizing, or coagulating tissue.
A variety of structural arrangements might be used to support the surgical instrument at the surgical site during robotic surgery. It has previously been proposed to support the surgical instrument with a mechanical linkage that is driven by the servomotors so that movement of the hand input devices at the master controller causes the surgical instrument to move in a corresponding manner at the surgical site. The driven linkage or xe2x80x9cslavexe2x80x9d is often called a robotic surgical manipulator.
Robotic surgery has potential applications for a wide variety of surgical
Robotic surgery has potential applications for a wide variety of surgical procedures and settings. Patients may benefit from robotic surgery directed by a surgeon who is at a considerable distance from the patient. This may allow treatment of soldiers in a battlefield environment, or treatment of trauma victims at considerable distances from a skilled surgical staff. Of particular importance to the present invention, robotic surgery also may provide significant benefits for performing minimally invasive surgical procedures located near the surgeon, but which are best performed within internal surgical sites which are difficult and/or impossible to access directly using a surgeon""s hands.
In traditional minimally invasive surgery, elongate surgical instruments are introduced to an internal surgical site, often through trocar sleeves or cannulas. The surgical site often comprises a body cavity, such as the patient""s abdomen. The body cavity may optionally be distended using a clear fluid such as an insufflation gas. Such minimally invasive procedures are often performed under the direction of a surgical imaging system, typically by introducing an endoscope to the surgical site. In traditional minimally invasive surgery, the surgeon then manipulates the tissues using end effectors of the elongate surgical instruments by actuating the instrument""s handles while viewing the surgical site on a video monitor.
Robotically assisted minimally invasive surgery instead makes use of a servomechanism to actuate the surgical end effectors of the instruments. This allows the surgeon to operate in a comfortable position without looking one direction (towards the monitor) while manipulating handles of surgical instruments that are oriented in another direction (for example, into the patient""s abdomen). As more fully described in U.S. Pat. No. 5,696,837, the full disclosure of which is incorporated herein by reference, a computer processor of the servomechanism can be used to maintain the alignment between hand input devices of the controller with the image of the surgical end effectors displayed on the monitor using coordinate system transformations. This allows the surgeon to operate in a natural position using anthropomorphic hand input devices and motions aligned with the image display, despite the fact that the actual surgical instruments are inserted via otherwise awkward arbitrary access positions.
A variety of linkage arrangements have been proposed for use as a robotic surgical manipulator during minimally invasive robotic surgery. An exemplary linkage arrangement is described in U.S. Pat. No. 5,800,423, the full disclosure of which is incorporated herein by reference. In one embodiment, this linkage makes use of a parallelogram arrangement of members to hold an instrument having a shaft. Such a manipulator structure can constrain movement of the instrument having a shaft so that the instrument pivots about a center of spherical rotation positioned in space along the length of the rigid shaft. By aligning this center of rotation with the access point to the internal surgical site (for example, with the trocar or cannula at the abdominal wall during laparoscopic surgery), an end effector of the surgical instrument can be positioned safely by moving the proximal end of the shaft using the manipulator linkage without imposing dangerous forces against the abdominal wall. Alternative manipulator structures are described, for example, in U.S. Pat. Nos. 5,445,166; 5,855,583; 5,808,665; and 5,184,601; the full disclosures of which are incorporated herein by reference.
While the minimally invasive robotic surgery systems proposed to date appear to offer tremendous advantages for performing a wide variety of procedures, still further improvements would be desirable. In general, it would be desirable to provide improved structures and systems for performing robotic surgery. More specifically, it would be beneficial to enhance the efficiency and ease of use of these systems. For example, it would be beneficial to facilitate the alignment of a surgical manipulator with a desired surgical access point. It would further be desirable to allow the surgeon to begin manipulating tissues immediately upon insertion of the surgical instruments and imaging system, with little or no delay in aligning the hand input devices with the actuation servomechanisms. It would further be desirable to provide robotic surgery systems which could be moved between multiple operating rooms without requiring major structural modifications, complex alignment procedures, or unusual peripheral equipment for the operating room, hospital, or procedure site. It would be best if these improvements allowed normal operating room personnel to rapidly arrange and prepare the robotic surgery system for surgery with little or no specialized training, and with as little impact as possible on the overall cost and complexity of the system.
The present invention provides improved robotic surgery systems, structures, and methods. In general, the invention enhances the efficiency and accuracy of robotic systems by providing techniques for aligning the motion and structure of the robotically controlled manipulators and end effectors with both the internal surgical site and each other. In many embodiments, the invention makes use of manually positionable linkages supporting the surgical instruments. These linkages will often maintain a fixed configuration and/or position until a brake system is released. While the brake is held in a released mode, the fixable linkage allows the operating room personnel to manually move the linkage into alignment with the surgical site. The brake system will often fix the configuration of these passive linkages whenever the operator lets go, thereby avoiding inadvertent movement of the surgical instruments. In the exemplary embodiment, manually repositionable joints of the positioning linkage allow the operator to translate the surgical manipulator and instrument in three dimensions, and to orient the surgical instrument by rotating the manipulator and instrument about three axes of rotation. Positioning of these structures is generally facilitated by using a counter-balanced linkage system, and/or by using an inherently balanced linkage system (for example, a selective Compliance Assembly Robot Arm or xe2x80x9cSCARA,xe2x80x9d a revolute arm in which the joint axes are vertical).
Advantageously, once the linkages supporting the surgical manipulator, instruments, and the imaging mechanism are in position, the robotic system can automatically calculate the desired coordinate system transformations so as to align hand inputs at the master controller relative to a display system with the displayed movements of the surgical instruments end effector. This capability can be provided by including a sensor system coupled to the fixable linkage. By measuring the angle of each rotational joint and the position of each sliding joint, a processor of the servomechanism can ensure that when the surgeon moves a hand input device to her right, the image of the end effector moves to the right on the controller""s display. Multiple fixable positioning linkages will often extend from a common base to the driven linkages of the robotic surgical manipulators, so that the manipulator structures can be easily moved to the desired position for surgery, and so that the relative position of each manipulator can be calculated from the sensor system. This also allows positioning of the manipulators while the surgical instrument is at or near the center of travel of the manipulator, thereby decreasing the possibility that a surgical procedure will be interrupted by a limitation in the range of motion of the manipulator.
In a first aspect, the invention provides a robotic surgery system comprising a base, a surgical end effector, and robotic linkage supporting the end effector relative to the base. The linkage comprising a plurality of driven joints coupled to a servomechanism for moving the end effector so as to manipulate tissues. The linkage also includes a plurality of releasably fixable joints for pre-configuring the linkage. A joint sensor system couples the fixable joints to the servomechanism. The sensor system generates joint configuration signals.
In another aspect, the invention provides a support structure for supporting a first robotic surgical manipulator relative to a second robotic surgical manipulator. Each surgical manipulator is coupled to a servomechanism so as to robotically manipulate tissues of a patient body with a surgical end effector. The support structure comprises a base coupled to the first manipulator. The manipulator support moveably supports the second manipulator relative to the base. A sensor system couples the manipulator support to the servomechanism. The sensor system transmits manipulator position signals to the servomechanism. Servomechanism calculates a position or orientation of the first manipulator relative to the second manipulator using the signals.
In yet another aspect, the invention provides a robotic surgery system comprising a base, a surgical end effector and a manipulator supporting the end effector. The manipulator has a rigid shaft and constrains movement of the shaft to rotation about a pivot point along the shaft. An imaging system is oriented toward the end effector. The imaging system has a field of view defining a coordinate system. A linkage supports the manipulator relative to the base. A brake system restrains articulation of the linkage. The brake system is releasable to allow manual movement of the pivot point of the manipulator relative to the base. A servo-mechanism drivingly engages the manipulator for robotic manipulation of tissues with the end effector. A hand input controller is coupled to the servomechanism. The controller has a controller coordinate system. A sensor system is coupled to the linkage so as to generate linkage configuration signals. A processor is coupled to the sensor system and the servomechanism. The processor uses the linkage position signals to calculate a coordinate system transformation so as to coordinate controller inputs with a displayed image of the end effector.
In yet another system aspect, the invention provides a transportable robotic surgery system comprising a cart having rolling elements for moving the cart between operating rooms. A plurality of robotic arms are supported by the cart. A plurality of surgical implements are supported by the arms. A control station is couplable to the cart for directing robotic surgery.
In a first method aspect, the invention provides a method for preparing for robotic surgery. The method comprises maintaining driven joints of a robotic surgical manipulator sufficiently near mid-points of travel of the joints, so as to avoid interference with a limit of travel of the manipulator within an intended worksite. The robotic manipulator is pre-positioned by manually articulating a linkage (the linkage generally supporting the manipulator relative to a base) while maintaining the driven joints near the mid-points. The positioned manipulator is restrained with a brake system so as to prevent articulation of the linkage.
In another method aspect, the invention provides a method for performing robotic surgery. The method comprises positioning a robotic surgical manipulator by manually articulating a linkage. The positioned manipulator is restrained with a brake system so as to prevent manual articulation of the linkage. A surgical end effector, which is supported by the positioned manipulator, is imaged in an imaging coordinate system. The restrained manipulator is actuated with a servomechanism by actuating a controller in a controller coordinate system so as to robotically manipulate tissue with the end effector. The controller coordinate system is transformed to the imaging coordinate system by sensing joint configurations of the restrained linkage. The imaged end effector is displayed so that controller inputs correlate with end effector movements.
In yet another method aspect, the invention provides a method for performing robotic surgery. The method comprises manually moving a manipulator relative to a base by articulating a plurality of fixable joints. A brake is actuated to inhibit inadvertent manual movement of the positioned end effector from articulation of the fixable joints. Tissue is manipulated with the end effector by actuating a plurality of driven joints of the linkage with a servomechanism. Positions of the fixable joints are sensed and transmitted to the servomechanism.